NEWGARDEN: A computer program to model the population dynamics and genetics of establishing and fragmented plant populations

Abstract

Conservation of plants often involves isolated in situ or ex situ protective restoration or supplemental plantings. Plant preservation also frequently involves maintenance of recently fragmented populations. The effects of the spatial patterning of the initial target species individuals in such situations on future population growth and genetic diversity maintenance are commonly difficult to predict, especially given that plants have varying life history characteristics. NEWGARDEN allows users to create a virtual preserve or fragment of specified size, place initial individuals at designated locations (the program is spatially explicit using a grid system), and follow population development stemming from bouts of mating influenced by user-specified life history characteristics (e.g., genetic diversity of the initial individuals; age-specific mortality; age-specific reproduction; gene dispersal distances; etc.). Output, which can be reported for the entire population data set and/or specified regions of the preserve or fragments after each bout of mating, includes total population and individual newest cohort data on the number of individuals, total number of founding alleles retained, observed heterozygosity, expected heterozygosity, and FIT. Use of the program is illustrated with a NEWGARDEN analysis of the effects of varying founder pattern and gene dispersal distance on population growth and genetic diversity for an annual plant. © 2013 The Author(s).